The present invention relates to a circuit switching device (a service plug) for opening an electric circuit and cutting off the current of the circuit, and particularly relates to a circuit switching device suitable for an electric automobile and others provided with a high-voltage circuit for driving a motor.
In the switchboard of a high-voltage circuit and others, there is a circuit switching device designed so that an operator is prevented from getting electric shock by detaching a plug provided to the switchboard from a terminal fixed in the body of the switchboard and cutting off the current of the circuit when the operator opens the cover of the switchboard.
Recently, attention is paid to an electric automobile as a pollution-free vehicle which does not exhaust exhaust gas. Also in the electric automobile, since a high-voltage circuit for driving a motor is provided, the current of the circuit is required to be cut off for the same reason as the above in maintenance service. From such a request, in a conventional electric automobile, there has been proposed a circuit switching device (connector device) in which a high-voltage circuit is stored inside a switchboard and the high-voltage circuit is automatically opened when the cover of the switchboard is opened.
FIG. 10 is a perspective view showing a conventional connector device and FIG. 11 is a sectional view showing a process in which the cover of the conventional connector device is shut. A female connector 3 is fixed inside a box-shaped housing 1 the top face of which is open, and the female connector 3 can be connected to external high-voltage cables 5a and 5b via each connector terminal 6. A cover 7 for opening or closing the opening is provided to the housing 1 and is turned around a turning shaft 9 as the center. A guide 11 is provided to the cover 7, and holds a male connector 13 and a guide member 15 which can be moved in the direction perpendicular to the turning shaft 9. A spring 17 shown in FIG. 11 is arranged between the internal wall of the guide 11 and the male connector 13 and presses the male connector 13 and the guide member 15 in the direction in which they approach the turning shaft 9.
In a connector device -19 constituted as described above, when the cover 7 is shut, the male connector 13 approaches the female connector 3, drawing an arc-shaped locus with the turning shaft 9 as the center. Therefore, the male connector 13 is moved in the direction in which it goes away from the turning shaft 9 against pressure by the spring 17 when the guide member 15 comes in contact with an internal wall 20a of a guide hole 20 in a process in which the male connector 13 is fitted into the female connector 3, is again moved by pressure by the spring 17 in the direction in which the male connector approaches the turning shaft 9, is fitted in the female connector 3, absorbing dislocation caused by the arc-shaped locus in the fitting process, and electrifies the high-voltage cables 5a and 5b.
In the meantime, when the cover 7 is opened, the male connector 13 is detached from the female connector 3, being moved again in the direction in which the male connector approaches and goes away from the turning shaft 9, opens a high-voltage circuit between the high-voltage cables 5a and 5b and as a result, can automatically cut off the current of the circuit.
However, in the above conventional connector, since the male connector 13 is provided on the cover 7, it is moved, drawing an arc-shaped locus, therefore, the male connector is required to be pressed by the spring 17 so that the male connector can be moved so as to absorb dislocation caused in a process in which the male connector is fitted into the female connector 3, and there is a problem that the structure is complicated and the number of the parts is increased.
There is also a problem that distortion is caused between the male connector and the female connector in fitting because the male connector 13 is moved, drawing an arc-shaped locus.
Further, in the conventional connector, since a handle such as a lever is not provided-to the cover 7, an operation for opening or shutting is difficult. In the meantime, there is a problem that if a handle is protruded from the cover 7, it becomes an obstacle in an electric automobile and the like the space of which is limited, while a fold type handle cannot hold force required to shut the cover 7 and satisfactory operability can be hardly obtained.